The notion of food security has an important history as a key concept for 20th‐century policymakers. Two overarching perspectives on food security are identified. One centred on raising production as the core answer to under‐consumption and hunger. The other is an emerging perspective, more social and ecological, accepting the need to address a complex array of problems, not just production. The first is primarily agricultural‐focused; the latter a food systems approach. From its inception in post‐World War 2 international reconstruction, the UN and governments have given tackling hunger a high profile, via a changing package of policy measures. Within a few decades, the production‐oriented approach or paradigm was being questioned by the emerging paradigm with its more complex, multi‐focused notion of the challenges ahead. When oil and agricultural commodity prices spiked in 2007–8, the complex agenda was marginalised by a renewed international focus on primary production and the needs of low‐income countries. Against this background, the paper explores the diversity of perspectives on what is meant by food security, concluding that the core 21st‐century task is to create a sustainable food system. This requires a more coherent policy framework than currently exists, a goal thwarted by competing solutions vying for policy attention and policy failure thus far to integrate the complex range of evidence from social as well as environmental and economic sources into an integrated policy response.

It is well known that food has a considerable environmental impact. Less attention has been given to mapping and analysing the emergence of policy responses. This paper contributes to that process. It summarises emerging policy development on nutrition and sustainability, and explores difficulties in their integration. The paper describes some policy thinking at national, European and international levels of governance. It points to the existence of particular policy hotspots such as meat and dairy, sustainable diets and waste. Understanding the environmental impact of food systems challenges nutrition science to draw upon traditions of thinking which have recently been fragmented. These perspectives (life sciences, social and environmental) are all required if policy engagement and clarification is to occur. Sustainability issues offer opportunities for nutrition science and scientists to play a more central role in the policy analysis of future food systems. The task of revising current nutrition policy advice to become sustainable diet advice needs to begin at national and international levels.

The rise of food security up international political, societal and academic agendas has led to increasing interest in novel means of improving primary food production and reducing waste. There are however, also many ‘post-farm gate’ activities that are critical to food security, including processing, packaging, distributing, retailing, cooking and consuming. These activities all affect a range of important food security elements, notably availability, affordability and other aspects of access, nutrition and safety. Addressing the challenge of universal food security, in the context of a number of other policy goals (e.g. social, economic and environmental sustainability), is of keen interest to a range of UK stakeholders but requires an up-to-date evidence base and continuous innovation. An exercise was therefore conducted, under the auspices of the UK Global Food Security Programme, to identify priority research questions with a focus on the UK food system (though the outcomes may be broadly applicable to other developed nations). Emphasis was placed on incorporating a wide range of perspectives (‘world views’) from different stakeholder groups: policy, private sector, non-governmental organisations, advocacy groups and academia. A total of 456 individuals submitted 820 questions from which 100 were selected by a process of online voting and a three-stage workshop voting exercise. These 100 final questions were sorted into 10 themes and the ‘top’ question for each theme identified by a further voting exercise. This step also allowed four different stakeholder groups to select the top 7–8 questions from their perspectives. Results of these voting exercises are presented. It is clear from the wide range of questions prioritised in this exercise that the different stakeholder groups identified specific research needs on a range of post-farm gate activities and food security outcomes. Evidence needs related to food affordability, nutrition and food safety (all key elements of food security) featured highly in the exercise. While there were some questions relating to climate impacts on production, other important topics for food security (e.g. trade, transport, preference and cultural needs) were not viewed as strongly by the participants.